1. Field of the Invention
The present invention relates to an optical sensor unit for performing image photographing using an optical sensor, an optical sensor array, and a method of driving the optical sensor.
2. Related Background Art
In recent years, a digital still camera and a digital video camera have been widely available because they have a characteristic in which a video obtained by photographing can be readily viewed at a photographing location and a characteristic in which an image is stored in a hard disk of a personal computer and can be read using a monitor when necessary. In many cases, an optical sensor mounted to the digital cameras is composed of a solid-state image pickup element of a MOS structure including a metal, oxide, and semiconductor in which photoelectric conversion is made possible. The solid-state image pickup element is classified into an FET type and a CCD type according to an optical carrier moving system. In addition, those types of solid-state image pickup elements are used in various fields such as a copying machine and a scanner in addition to the above-mentioned cameras.
As shown in FIG. 24, the optical sensor includes a large number of optical sensor elements 21 arranged in matrix within an area 24 which receives light related to a video. A driver circuit which is composed of a column circuit 25 and a row circuit 26 transmits/receives signals to/from the respective optical sensor elements 21 through respective wirings 22 and 23, thereby producing the entire image data.
For example, FIG. 25 shows a two-dimensional CMOS area sensor having pixels of two columns and four rows, which is described in the first embodiment in Japanese Patent Application Laid-Open No. 2000-004399. According to a CMOS circuit disclosed in Japanese Patent Application Laid-Open No. 2000-004399, timing signals for image recording are sent from a vertical scanning block circuit and a horizontal scanning block circuit to respective CMOS sensor elements through respective wirings and then pixel signals are read out therefrom. Therefore, the optical sensor represented by the solid-state image pickup element such as a CMOS sensor or a CCD sensor which has been used up to now has a structure in which electrical wirings run in matrix to connect at least two driver circuits with the respective optical sensor elements.
On the other hand, when a 180° or 360° panoramic picture is photographed, it is desirable that the optical sensor elements are formed on a curved substrate. Therefore, it is required that the optical sensor has a structure which is resistant to deformation such as bending. In addition, a use in which an object is photographed as a three-dimensional stereoscopic video and published on Web is increased. In addition, according to the optical sensor which has been used up to now, for example, the optical sensor disclosed in Japanese Patent Application Laid-Open No. 2000-004399 as described above, light sensitivity is uniformly adjusted for the entire substrate.
Because each optical sensor is formed on the same flat substrate, an angle with respect to a subject is constant. Accordingly, when a region wider than the view angle of a wide angle lens is photographed, it is required that images in respective portions are photographed in advance and the photographed images are synthesized.
Also, when a single subject is photographed from different angles, it is necessary to change both the position and the orientation of the optical sensor for photographing as in the above-mentioned case. In addition, synthetic processing is required after the photographing. In the synthetic processing, positioning and sensitivity matching of respective images for keeping the continuity thereof are difficult. Therefore, there is a problem in that the synthetic processing is difficult.
Also, the entire sensitivity is determined in the conventional CCD sensor and the conventional CMOS sensor. Therefore, when a difference between a bright region and dark region in an image is large, it is necessary to adjust the sensitivity to either region. However, in this case, there arises the following problem. When the sensitivity is adjusted to the bright region, the dark region is difficult to view. When the sensitivity is adjusted to the dark region, the bright region uniformly becomes white.